Agglomerating granular material

ABSTRACT

An agglomerating technique in which a formulation containing a major amount of granular material and a minor amount of powdered material is throughly blended and fed through an agglomerator. This method provides a means for adjusting and controlling the bulk density of agglomerated products over ranges not readily obtained when agglomeration is performed with all powdered material.

United States Patent Mednis [451 May 2, 1972 54 AGGLOMERATING GRANULAR 3,485,637 12/1969 Adler et a]. ..99/DIG. 4 MATERIAL 3,143,428 8/1964 Reimers et al. ..99/DIG. 4

[72] inventor: Edmar J. Mednis, Woodside, NY. Primary Examiner-Frank W. Lutter Assistant Examinerwilliam L. Mentlik [73] Asslgnee' ga Foods Corpomlon Whlte Hams Attorney-Bruno P. Struzzi, Daniel J. Donovan and Thomas R. Savoie [22] Filed: Feb. 19, 1970 [2i] App]. No.: 12,855 [57] ABSTRACT An agglomerating technique in which a formulation containing a major amount of granular material and a minor amount [52] US. Cl. ..99/7l, 99/DIG. 432631711137, of powdered material is through), blended and fed through an 511 int. Cl. A23f 1/08 aggmmeram- This meflmd Pmmes a means adl'usling and [58] new of 099M164 23/313. controlling the bulk density of agglomerated products over 7 ranges not readily obtained when agglomeration is performed with all powdered material. [56] References Cited 5 Claims, No Drawings AGGLOMERATING GRANULAR MATERIAL BACKGROUND OF THE INVENTION Processes for agglomerating powders for the purposes of improved dispersibility, decrease in bulk density, and other characteristics are well known and are disclosed in many prior art patents such as U.S. Pat. Nos. 3,011,897, 3,143,428, and 3,485,637. These prior art patents indicate that one requirement for good agglomeration is the need for the small particle size of all'of the feed materials. It is generally thought that the finer the size of the feed materials the more successful will be the agglomeration. The reasoning for this assumption is that the fine particles have a greater surface area per unit weight than the coarser particles and, therefore, will offer more contact points for wetting and subsequent agglomeration. It has been assumed that agglomeration utilizing granular material will not be practical. This invention shows that with the proper selection of granular and powdered materials agglomerated products having improved characteristics and flexibility of their properties can be achieved.

Some problems which have arisen in the prior art with the agglomeration of all powdered feed materials have been difficulties in handling and conveying the powdery materials, a relatively high content of fine particles in the final product, and a relatively limited amount of flexibility in varying a bulk density of the final agglomerated product.

SUMMARY This invention utilizes feed material containing a major amount of granular particles to achieve agglomerated products and overcomes the disadvantages of using large quantities of powdery feed materials. The invention relates more particularly to the agglomerating of food particles to achieve a free-flowing product whose bulk density may be precisely controlled.

According to this invention granular materials are employed in the formulation of agglomerated products and the proper selection of the granular materials presents a new tool in achieving product characteristics not otherwise readily obtained. This invention utilizes powdery materials to act as binding agents for securing together the granular particles. It is contemplated according to this invention that agglomerated products comprising of up to about 85 percent granular material may be produced. As will be seen, this invention finds use in the formulation of low calorie sugar substitutes, powdered beverage products, and soluble cofl'ee products.

It is an object of this invention to produce agglomerated materials having a low level of fine material.

It is another object of this invention to be able to control the bulk density of an agglomerated material.

It is also an object of this invention to eliminate a large percent of powdered feed material in agglomeration processes.

These and other objects of this invention will become apparent from the description herein.

DESCRIPTION OF THE INVENTION 1 In this invention agglomerated products, especially food products, are produced by employing feed materials comprising a major amount of granular material with a minor amount of powdered material. According to this invention the feed materials may include from 50 percent up to about 85 percent of the granular material and preferably from 70 to 85 percent granular material.

As used in this invention granular material is meant to include materials in which at least 50 percent by weight will be retained .on a 50 mesh screen (all meshes U.S. Standard Sieves) and/or in which at least about 90 percent will be retained on a 70 mesh screen and preferably in which essentially all the material is at least 200 microns in size.

The powdered material of this invention encompasses those powders in which essentially all the particles are less than 100 microns and preferably in which at least about 95 percent by weight will pass through a 200 mesh screen.

The concept of this invention utilizes the amount and size of the granular material to produce agglomerated products with certain desired physical characteristics such as bulk density. In addition, this invention employs powdery material to act as a "cement" between the larger granular particles and to produce strong and attractive agglomerates. It is possible to produce the agglomerates of this invention by using powdery materials. For instance, a readily dispersible sweetener can be produced using granular sugar and powdered sugar or a powdered beverage mix can be produced using granular food acid and powdered sweeteners.

A preferred embodiment of this invention is the agglomeration of granular freeze-dried cofiee with a powdered soluble coflee.

Freeze-dried coffee has met with wide consumer acceptance since it s many flavor advantages over the heretofore widely used spray-dried cofiee. However, some problems have arisen with the use of freeze-dried coffee and these problems are sought to be overcome by one of the embodiments of this invention.

It has been found that freeze-dried coffee posseses a rather light color which has not met with wide consumer appeal. Through the method of this invention granular freeze-dried coffee may be agglomerated with powdered soluble coffee and the color of the resultant coflee agglomerates will tend to be darker than the color of the freeze-dried granules. These agglomerate coffee clusters also possess a mottled surface similar in appearance to that of freshly ground roasted coffee.

Freeze-dried cofl'ee has also met with the problem of many fine particles that occur either in the original processing or subsequently develop from the breakage of the freeze-dried particles. These fine particles tend to accumulate at the bottom of a container (e.g.', glass jar) of freeze-dried coffee and present an unappealing appearance to the consumer. Through the method of agglomerating freeze-dried coflee with soluble cofiee powder the fine freeze-dried particles can be substantially eliminated.

In this agglomeration process the small particles of soluble coffee powder, such as spray-dried cofiee, tend to act as the cementing medium to bind together the particles of freezedried coffee. These agglomerated cofl'ee particles possess good structural stability and appear to reduce the problem of breakage of the freeze-dried coffee particles.

It has been found that the incorporation of up to 30 percent by weight of the spray-dried coffee with at least about 70 percent by weight of freeze-dried coffee does not noticeably detract from the excellent flavor normally associated with l00 percent freezedried cofi'ee. This coffee product also possesses economic advantages since the less costly spray-dried coffee can be substituted in part for the more expensive freeze-dried In this embodiment of the invention the particles of spraydried cofiee of less than microns in size are employed. These particles are usually obtained by grinding regular spraydried cofl'ee solids (about 100 to 300 microns) in a commercial mill (e.g., Fitz Mill); however, any procedure which will produce spray-dried cofiee solids having essentially all the particles less than 100 microns in size may be employed.

The composite granular and powdered feed material employed in this invention is agglomerated in any of the prior art agglomerating equipment operating under conditions which will be readily apparent to one skilled in the art.

This invention is further described but not limited by the following examples.

EXAMPLE I Granular Sized Material:

Fine Granular Sugar (less than 7% on 20 mesh, more than 35% cumulative on40 mesh, lessthan l5% through 70 mesh) Powdered Sized Material:

Weight 83.72

Corn Syrup Solids, 24 DH. (Frodex) Sodium Cyclamate Sodium Saccharin Salt Carboxymethylcellulose (CMC) 0.ll4 0.2l 0.016

' a completely powdered condition, agglomerated under similar conditions. It was found that fines (i.e., those particles through a 200 mesh screen) were present in the agglomerated products of this example in the amount of only 0.8 percent; whereas, when the all powdered feed material was agglomerated the fines amounted to 16.9 percent of the final product.

EXAMPLE II A dry beverage mix with the formulation shown below and with a final screened bulk density of 0.50 g/cc was required to meet package fill specifications. This could not be achieved by agglomerating a mix containing ground citric acid because too low a density resulted. The density specification could only be met by using a fine granular citric acid in the feed as shown below.

Granular Material:

Fine Granular Citric Acid (anhydrous) (at least 50% on 40 mesh) Powdered Material:-

Dextrose (2001 Cerelose) Corn Syrup Solids, 24 D.E. (Frodex) Corn Starch Lemon Solids Color-Flavor Agents the product of this example was able to achieve the desired bulk density, was lower in fines content, and had better color development.

EXAMPLE HI Spraydried coffee having a particle size distribution of between 100 and 300 microns is ground in a hammer mill (Fitzpatrick Model D16, equipped with a 4 mesh screen) to produce a powder wherein at least 95 percent of the particles were less than 50 microns in size. This ground spray-dried coffee is throughly mixed in a ribbon blender in accordance with the following fonnulation.

Weight 70.5

Granular Material:

Granular Freeze-Dried Coffee (at least 50% on 30 mesh less than 20% through 50 mesh) Powdered Material:

Spray-Dried Cofi'ee (ground in hammer mill) This mix is agglomerated in a standard commercial agglomerator with a steam inlet temperature of 225 F. and a drying air temperature of 425 F. The agglomerated product presented an appearance more similar to ground roasted coffee than the normal freeze-dried coffee and the product of this example produced a coffee beverage rated equal in flavor to the 100% freeze-dried cofiee beverage.

Having thus described this invention what is claimed is:

1. A method of agglomerating granular food materials wherein the bulk density of the agglomerated product may be controlled comprising the steps of blending and agglomerating from 50 to percent by weight of granular material in which essentially all of the granular particles are at least 200 microns in size with from 50 to 15 percent by weight of a powdered food material in which at least percent by weight of the powdered particles will pass through a 200 mesh screen.

2. The method of claim 1 wherein the granular material is blended at from 70 to 85 percent by weight.

3. The method of claim 1 wherein the granular material is freeze-dried cofi'ee.

4. The method of claim 3 wherein the powdered material is ground spray-dried coflee.

5. The method of claim 4 wherein at least 95 percent of the ground, spray-dried, coffee particles are less than 50 microns in size. 

2. The method of claim 1 wherein the granular material is blended at from 70 to 85 percent by weight.
 3. The method of claim 1 wherein the granular material is freeze-dried coffee.
 4. The method of claim 3 wherein the powdered material is ground spray-dried coffee.
 5. The method of claim 4 wherein at least 95 percent of the ground, spray-dried, coffee particles are less than 50 microns in size. 